glibc/sysdeps/aarch64/Makefile
Ben Woodard b118bce87a elf: Fix runtime linker auditing on aarch64 (BZ #26643)
The rtld audit support show two problems on aarch64:

  1. _dl_runtime_resolve does not preserve x8, the indirect result
      location register, which might generate wrong result calls
      depending of the function signature.

  2. The NEON Q registers pushed onto the stack by _dl_runtime_resolve
     were twice the size of D registers extracted from the stack frame by
     _dl_runtime_profile.

While 2. might result in wrong information passed on the PLT tracing,
1. generates wrong runtime behaviour.

The aarch64 rtld audit support is changed to:

  * Both La_aarch64_regs and La_aarch64_retval are expanded to include
    both x8 and the full sized NEON V registers, as defined by the
    ABI.

  * dl_runtime_profile needed to extract registers saved by
    _dl_runtime_resolve and put them into the new correctly sized
    La_aarch64_regs structure.

  * The LAV_CURRENT check is change to only accept new audit modules
    to avoid the undefined behavior of not save/restore x8.

  * Different than other architectures, audit modules older than
    LAV_CURRENT are rejected (both La_aarch64_regs and La_aarch64_retval
    changed their layout and there are no requirements to support multiple
    audit interface with the inherent aarch64 issues).

  * A new field is also reserved on both La_aarch64_regs and
    La_aarch64_retval to support variant pcs symbols.

Similar to x86, a new La_aarch64_vector type to represent the NEON
register is added on the La_aarch64_regs (so each type can be accessed
directly).

Since LAV_CURRENT was already bumped to support bind-now, there is
no need to increase it again.

Checked on aarch64-linux-gnu.

Co-authored-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>
Reviewed-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>
(cherry picked from commit ce9a68c57c)

Resolved conflicts:
	NEWS
	elf/rtld.c
2022-04-12 13:33:10 -04:00

70 lines
1.6 KiB
Makefile

long-double-fcts = yes
ifeq (yes,$(aarch64-bti))
# Mark linker output BTI compatible, it warns on non-BTI inputs.
sysdep-LDFLAGS += -Wl,-z,force-bti
# Make warnings fatal outside the test system.
LDFLAGS-lib.so += -Wl,--fatal-warnings
LDFLAGS-rtld += -Wl,-z,force-bti,--fatal-warnings
endif
ifeq ($(subdir),elf)
sysdep-dl-routines += dl-bti
tests += tst-audit26 \
tst-audit27
modules-names += \
tst-audit26mod \
tst-auditmod26 \
tst-audit27mod \
tst-auditmod27
$(objpfx)tst-audit26: $(objpfx)tst-audit26mod.so \
$(objpfx)tst-auditmod26.so
LDFLAGS-tst-audit26 += -Wl,-z,lazy
tst-audit26-ENV = LD_AUDIT=$(objpfx)tst-auditmod26.so
$(objpfx)tst-audit27: $(objpfx)tst-audit27mod.so \
$(objpfx)tst-auditmod27.so
$(objpfx)tst-audit27mod.so: $(libsupport)
LDFLAGS-tst-audit27 += -Wl,-z,lazy
tst-audit27-ENV = LD_AUDIT=$(objpfx)tst-auditmod27.so
endif
ifeq ($(subdir),elf)
sysdep-dl-routines += tlsdesc dl-tlsdesc
gen-as-const-headers += dl-link.sym
tests-internal += tst-ifunc-arg-1 tst-ifunc-arg-2
ifeq (yes,$(aarch64-variant-pcs))
tests += tst-vpcs
modules-names += tst-vpcs-mod
LDFLAGS-tst-vpcs-mod.so = -Wl,-z,lazy
$(objpfx)tst-vpcs: $(objpfx)tst-vpcs-mod.so
endif
endif
ifeq ($(subdir),csu)
gen-as-const-headers += tlsdesc.sym
endif
ifeq ($(subdir),gmon)
CFLAGS-mcount.c += -mgeneral-regs-only
endif
ifeq ($(subdir),math)
CPPFLAGS += -I../soft-fp
endif
ifeq ($(subdir),misc)
sysdep_headers += sys/ifunc.h
sysdep_routines += __mtag_tag_zero_region \
__mtag_tag_region
endif
ifeq ($(subdir),malloc)
sysdep_malloc_debug_routines = __mtag_tag_zero_region __mtag_tag_region
endif